Air filter for endonasal use

ABSTRACT

A description is given of an endonasal filter including two essentially planar filtering components joined at their respective ends by a flexible element mounted, similar to a spring, across the cartilage between the two nostrils. The shape of the filtering components is that of a lunette as is the shape of the section at entry to the channel communicating with the nasal cavities. The filtering components are joined by a thin piece of plastic shaped to form a U-bend, the two parallel sides of which extend towards the filtering components on whose surfaces they assume the form of an oval that supports the component and to which it is made to adhere by application of heat.

FIELD OF APPLICATION OF THE INVENTION

The present invention relates to filtering devices for environmentalair, and more precisely to a device fitted inside the nose to filter theair breathed in.

REVIEW OF THE ART AT PRESENT KNOWN

Under certain conditions it is of primary importance that air from theenvironment should be filtered before being breathed into the lungs ifmore or less serious harm to the respiratory and other systems is to beavoided. Urban areas subjected to heavy automobile traffic, for example,are highly polluted by exhaust from cars and by the unburnt particlesfrom diesel engine combustion. Other sources of air pollution occur inhuman activities where processes, such as transport of buildingmaterials, marble quarrying, coachwork painting and many others, producea highly dangerous dust known as micro-particles. Even in thecountryside, where these activities are not present, various forms ofpollution still exist such as pollen from plants, germs, and others.Finally, domestic dust, that contains mites and often hair from thecoats of animals, may be considered as a polluting agent especially inwinter when heating systems are functioning. The diameters ofmicroparticles of dust vary from 0.5 μm upwards.

Air filtering devices can be divided into two categories: filters placedwhere air enters closed environments and filters applied to devices wornby the person. The present invention is concerned with the second typeonly. Filters worn on the person include well-known forms such as facialmasks of various kinds, fitted with more or less sophisticated filtersaccording to the prevailing type of pollution. Such filters range fromspecialised anti-gas masks down to the simple kinds used in surgery.These latter may be considered as closest to the presently-known artthat concerns this invention and should therefore be briefly described.Simple facial masks comprise a filtering component shaped to fit thelower part of the wearer's face covering the nose, mouth and chin. Thefiltering component is held close against nose and mouth by ties orelastic bands that are passed round the back of the head to hold themask in place, in such a way that air is prevented from entering alongthe edge and must pass through the filtering material used to make themask. Closely-woven cotton fabrics are the most popular ones for thispurpose but, generally speaking, natural or synthetic materials ofdifferent weaves can be used such as non-woven fabric, cotton and otherfibres, micro-porous resins, carbon granules and various salts.

Though useful for the purpose, these simple masks are somewhat unsightlyand seem needless unless air pollution is so high as to make totalfiltering of environmental air necessary. Where pollution is not soserious it would appear prudent to assist the natural filtering functionof the nasal cavity while leaving the mouth free, but this cannot bedone with an ordinary mask. Devices for introducing purified air oroxygen straight into the nasal cavity exist; these consist of twoplastic tubes that fit into a nasal pillow to insert inside the nostrilswith a sling arrangement at the back of the head to hold the two tubesin place. Such devices however require separate filters and a supply ofoxygen which makes them too bulky to be portable.

The German patent DE 668395 describes an endonasal filter having twoflat capsules to be introduced into the nasal cavities, each capsulebeing composed of two punched coverage plates (a, b) holding a discoidfilter (c) between them, the two external plates (b, b) of the twocapsules are connected to each other by a flexible rib (d), wherein forevery capsule the two plates (a, b) are joined together by an encirclingrubber ring (e). This endonasal filter is too rigid to match withvarious noses, and too complicated to be really disposable

The U.S. Pat. No. 2,282,681 describes an endonasal filter comprising aframe constructed from a single piece of wire and including a U shapedbridge portion, for attaching to the nose septum, having a portion ofsaid wire extending laterally from each end thereof and looped toprovide a shield in the shape of a figure 8 for supporting a filterthereon. One loop of the 8 is smaller than the other, thus tapering theshields to conform with the shape of the nasal passages at the nostrils.The two filter elements are a sort of pouches, preferably of clothmaterials, with an elastic member that is sewn along the edge. They aremounted along the shields kept in a stretched condition. This endonasalfilter is limited to filter elements made of materials withoutautonomous flexibility, so the looped ends of the connecting element arethe only ones deputed to fit with the lumen of the nose channel.

SUMMARY OF THE INVENTION

Purpose of the present invention is to overcome the above drawbacks andoffer an air filtering device to be applied to the nose only, a devicethat is not immediately noticeable and that takes up little space.

Subject of the invention is therefore an air filter as described in theclaims.

According to the invention the filter comprises two essentially planarendonasal filtering components the ends of which are joined to aflexible connection that extends across the piece of cartilage betweenthe two nostrils, similar to a spring. The essentially flat filteringcomponents are lunette-shaped like the lumen on the channel givingaccess to the nasal cavities, and this form makes them adaptable tonoses of different shapes because, although nostrils differ from oneperson to another, the lumen is fairly uniform in all cases. The surfacearea of one face of the filtering component is slightly greater than thearea of the section at entry to the endonasal channel where it is tofit, so that it can be partially bent inwards along the edge and can fitclosely against the wall of the lumen.

As regards the material to use for the filtering component, care shouldbe taken to choose a material that is not thick enough to impede normalbreathing. In this connection any person competent in the field wouldknow which material is best to use according to the prevailing type ofpollution. The filtering components are joined together by a thinU-shaped bar, its two parallel side pieces extending towards saidcomponents on which they form a roughly oval-shaped support whichadheres to the filtering surfaces. For this connecting part plasticmaterial is suitable such as transparent polyethylene, or else a thinsteel wire bent to form an arch. The type of material, thickness, radiusof curvature of the U-shaped arch and length of the two shanks must besuch as to ensure an elastic fit against the cartilage between thenostrils and the two filtering components that must enter well insidethe nostrils to intercept the lumen at entry to the nasal cavities.These requirements too can be easily satisfied from common knowledge.

The filtering device as here invented is highly practical to use. It isin no way unsightly being almost completely invisible. Production costsare extremely low. It can preferably be made in three sizes: small,medium and large. It is a device of the disposable type but can also beused several times for short periods. The life of its effectiveness as afilter depends on the concentration of polluting substances in the air;directions for use are in any case given on the package.

SHORT DESCRIPTION OF THE FIGURES

Further purposes and advantages of the present invention will be madeclearer by the following detailed description of a manufactured exampleand by the attached drawings given for explanatory purposes in no waylimited to these examples, wherein:

FIG. 1 shows a perspective view of an endonasal filter according to thepresent invention;

FIG. 2 shows a perspective view of a different version;

FIG. 3 shows a side view of a detail of connection between a spring forapplication of the filter and a filtering substrate;

FIGS. 4 and 5 show an example of how the endonasal device in FIG. 1 isfitted inside the nose.

DETAILED DESCRIPTION OF SOME PREFERRED FORMS OF REALIZING THE INVENTION

With reference to FIG. 1, it will be seen that the endonasal filtercomprises two filtering components, 1 and 2, adjacent to each other,substantially flat and lunette-shaped, with between them a connectingelement 3, acting as a spring. Element 3 is a single thread-like pieceforming an arch, 4, the two ends of which are extended to become twoparallel shanks 5 and 6 that reach as far as the two filteringcomponents 1 and 2, and make perpendicular contact with the surfaces ofsaid components. The shanks are then bent to form two oval-shapedelements 7 and 8 that rest on the filtering components lying closer totheir inner edges than to their outer edges, and measuring about onequarter of the length of said components. The filtering components arethinner than the diameter of the thread-like arch 3, and adhere to theoval-shaped elements 7 and 8 resting on them. As far as concerns thematerial of the parts shown in the figure, this has already beenexplained above, as well as the geometrical dimensions and thicknesses.

According to a preferred form of realization, in which the connectingelement 3 is made of plastic material as are the filtering components 1and 2, said components 1 and 2 adhere to the oval-shaped elements 7 and8 without the need for glue as it is sufficient to press them againstthe material while still hot in the press in order to fix thempermanently.

FIG. 2 shows a variant in which, compared with the previous figure, thebases of the two shanks 5 and 6 consist of two small solid disks 9 and10; these too can be made by moulding the same material as that of theshank, and then fixing them as above to the filtering components 1 and2.

FIG. 3 shows how the shank 5, adhering to the filtering component 1, isbent to form oval element 7; the thicknesses shown here are close toreality. Although the filtering components 1 and 2 are so thin, thegreater thickness of the oval parts 7 and 8, as well as their extension,together confer a certain degree of rigidity to the central area offiltering components 1 and 2, which helps to insert them to the requireddepth.

FIG. 4 illustrates an example of how the endonasal filter is applied.The figure shows the base of a nose 11, as seen from the nostrils 13 and14, into which the two filtering components 1 and 2 have been inserted,joined by the central connecting element 3 placed across the cartilage12 that separates the two nostrils. It will be seen that the shape ofthe filtering components 1 and 2 follows the outline of the nostrils 13and 14 fairly closely and provides ample coverage when spread out.

In FIG. 5 the nose 11 is seen in profile, showing the connecting element3 placed crosswise in relation to the cartilage 12, acting as a springto keep the filtering components 1 and 2 in the position indicated bythe dotted line. The filtering components 1 and 2 are inserted into thenostrils 13 and 14 by picking up the arch 4 between two fingers andpushing it inside the nose. This pressure widens the shanks 5 and 6 thusalso altering the curve of the arch 4 which, being elastic, tends toreturn to its initial curve so exerting two opposing forces on theshanks 5 and 6; since these forces are both directed against thecartilage 12, the filter is thus kept in its correct position.

In the figure it will be seen that there is a slight adaptation inwardsof the filtering component 2 (the same happens with component 1) as theintercepting surface is greater in relation to the section at the pointof entry into the channel. This prevents unfiltered air from entering atthe sides.

From the description given of a preferred realization, it is clear thatchanges can be made to it by competent persons without departing fromthe invention as described in the following claims.

1. An endonasal filtering device for air from the environment,consisting essentially of: two filtering components (1, 2), joined to aflexible U-shaped connection (3) with two shanks (5, 6) that extendsacross the piece of cartilage between the two nostrils, as a spring,wherein, said filtering components (1, 2) are essentially flatcomponents, lunette-shaped corresponding to the lumen of the channelgiving access to the nasal cavities, and said U-shaped flexibleconnection (3) comprises, at each end of the shank, joining means (7, 8,9, 10) permanently fixed to the respective filtering component (1, 2),wherein, a surface area of each filtering component (1, 2) forintercepting incoming air is greater than the area of the section atentry to the endonasal channel, so as to be partially bent inwards alongthe edge and fit closely against the wall of the lumen of said channel,and the thickness of the flat filtering components (1, 2) is less thanthe thickness of the flexible connection (3).
 2. The endonasal device asin claim 1, wherein, said shanks (5, 6) are substantially perpendicularto the surface of the corresponding flat filtering component (1, 2), andsaid joining means (7, 8, 9, 10) lie on the plane of said filtering flatcomponents (1, 2).
 3. The endonasal device as in claim 1, wherein, saidjoining means (7, 8, 9, 10) consist of the ends of said shanks (5, 6)curved to form a roughly oval-shaped support adhering to the surface ofthe filtering flat components(1, 2).
 4. The endonasal device as in claim1, wherein said joining means (7, 8, 9, 10) consist of the ends of saidshanks (5, 6) flattened to form two disks (9, 10) adhering to thesurface of the filtering flat components(1, 2).
 5. The endonasal deviceas in claim 1, wherein said flexible connection (3) is made of plasticmaterial.
 6. The endonasal device as in claim 1, wherein said flexibleconnection (3) is made of steel wire.
 7. An endonasal filtering devicefor air from the environment, consisting essentially of: a flexibleU-shaped connection (3) with two shanks (5, 6) configured to extendacross the piece of cartilage between two nostrils; and two filteringcomponents (1, 2) joined to the flexible U-shaped connection (3) withtwo shanks (5, 6), wherein, said filtering components (1, 2) areessentially flat components and are lunette-shaped corresponding to alumen of a channel giving access to nasal cavities, and said U-shapedflexible connection (3) comprises, at an end of each shank, joiningmeans (7, 8, 9, 10) permanently fixed to the respective filteringcomponent (1, 2), wherein, a surface area of each filtering component(1, 2) for intercepting incoming air is greater than the area of thesection at entry to the endonasal channel, so as to be partially bentinwards along the edge and fit closely against the wall of the lumen ofsaid channel, and the thickness of the flat filtering components (1, 2)is less than the thickness of the flexible connection (3).